<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
    <script>
        // 目标：编写一个函数，接受一个数组作为参数，并返回数组中所有奇数的平均值（如果没有奇数则返回0）

        let arr = [2, 5, 8, 10, 15, 11, 22]

        function fn(a) {
            let sum = 0
            let average = 0
            for(let i = 0; i < a.length; i++) {
                
                if(a[i] % 2 !== 0) {
                    sum += a[i]
                    average++;
                }
            }
           if(average === 0) {
            return 0
           } else {
            return sum / average 
           }
            
        }
        document.write(fn(arr)); 
    </script>
</body>
</html>